EBIKE PROBLEM HELP!

[flotronics]

I have been building ebike's for a couple years now and I have yet to experience anything like this before.

I purchased a 96v hub motor kit that came with controller throttle and hub motor. everything matches up so i know all wiring is good. I am using 72v 10 ah built from 38120s headway batteries which is run is series with a 24v 10ah 38120s headway setup. I accidentally had the BMS wired up wrong a couple of times and it caused damage to the BMS and some batteries. Since then I have replaced batteries and BMS and double and triple checked that everything is wired up and I know it is now because i was riding ebike with no problem for one day. That same day the bike just cut off and wouldn't move, at about 5 ah of use(1/2 of what it should of cut off at). When applying throttle the bike tries to go but cuts off after it moves about an inch. also every time this happens it kills one cell(goes to 0v) in the pack that i built. Every time I replace this cell the same one in the same spot goes bad once I hook it up and apply throttle.

also whenever i turn the bike on the voltage drops by 5 volts%%P. plus or minus. it never did this before and i was able to narrow it down to the two wires that connect throttle to controller. whenever i disconnect these wires and turn the bike on the voltage doesn't drop anymore.


Please help me diagnose this problem.. I have spent way too much money replacing batteries and BMS. and i recently just ordered a custom battery box to be 3D printed that I designed using AutoCAD so I want it to all be working by the ETA.

Thanx in Advance.

 

[flotronics]

I have been building ebike's for a couple years now and I have yet to experience anything like this before.

I purchased a 96v hub motor kit that came with controller throttle and hub motor. everything matches up so i know all wiring is good. I am using 72v 10 ah built from 38120s headway batteries which is run is series with a 24v 10ah 38120s headway setup. I accidentally had the BMS wired up wrong a couple of times and it caused damage to the BMS and some batteries. Since then I have replaced batteries and BMS and double and triple checked that everything is wired up and I know it is now because i was riding ebike with no problem for one day. That same day the bike just cut off and wouldn't move, at about 5 ah of use(1/2 of what it should of cut off at). When applying throttle the bike tries to go but cuts off after it moves about an inch. also every time this happens it kills one cell(goes to 0v) in the pack that i built. Every time I replace this cell the same one in the same spot goes bad once I hook it up and apply throttle.

also whenever i turn the bike on the voltage drops by 5 volts%%P. plus or minus. it never did this before and i was able to narrow it down to the two wires that connect throttle to controller. whenever i disconnect these wires and turn the bike on the voltage doesn't drop anymore.


Please help me diagnose this problem.. I have spent way too much money replacing batteries and BMS. and i recently just ordered a custom battery box to be 3D printed that I designed using AutoCAD so I want it to all be working by the ETA.

Thanx in Advance.

 

[Icewrench]

Charge your battery and then check the voltage of each cell in the pack.
With 2 bms with a low volt cut off on each and a low volt cut off in the controller it could be any one of them stopping your bike. Same cell always going bad does sound like a bms issue. Might always be draining that cell.